Queue. Topic. Array Queue

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1 Queue Fundamental of Data Structures and Algorithms Topic o o Circular o o Circular 2 o Declaration int const queue_size=5; typedef struct int ; int ; int [queue_size]; arr_queue; array o IsEmpty / IsFull int IsEmpty(arr_queue *q) return(q->==queue_size); int IsFull(arr_queue *q) return(q->==(queue_size-1)); 3 4

2 5 o Create void create_queue(arr_queue *q) q->=queue_size; q->=queue_size; 6 o Enqueue void enq(int en_,arr_queue *q) if(isempty(q)) q->[0]=en_; q->=0; q->=0; else if(!isfull(q)) q->++; q->[q>]=en_; else printf("\nqueue Full"); 7 o Dequeue int deq(arr_queue *q) int de_=null; if(!isempty(q)) de_=q->[q->]; q->++; if(q->>q->) q->=queue_size; q->=queue_size; else printf("\nempty Queue"); return(de_); 8 o Front int (arr_queue *q) if(!isempty(q)) return(q->[q->]); else printf("\nempty queue");

3 9 o Rear int (arr_queue *q) if(!isempty(q)) return(q->[q->]); else printf("\nempty queue"); 10 o Clear void clear_queue(arr_queue *q) while(!isempty(q)) deq(q); o Count int count_queue(arr_queue *q) int count; if(!isempty(q)) count=(q->-q->)+1; else count=0; return(count); queue (integer) queue (integer) null null Queue full even array[0],[1] is empty

4 แบบฝ กห ด queue (integer) queue (integer) = 0 o ปร บเปล ยน array queue จาก code ท ก าหนด โดย ให แก ป ญหา queue เต มโดยท ย งม ท ว างเหล ออย ด านหน า โดยการใช การเล อนต าแหน งขณะท ท าการ dequeue o ในการปร บเปล ยนต องม การแก ไขฟ งก ช นใดบ าง 13 o Front constant = 0 o Changes Dequeue Function Circular array size queue (integer) queue (integer) 16 Circular o Declaration int const queue_size=5; typedef struct int ; int ; int [queue_size]; arr_queue; array Create and IsEmpty is same as.

5 17 Circular o IsFull int IsFull(arr_queue *q) if(q-> < q->) return((q-> - q->)==1); else return((q-> - q->)==(array_size-1)); 18 Circular o Enqueue void enq(int en_,arr_queue *q) if(isempty(q)) q->[0]=en_; q->=0; q->=0; else if(!isfull(q)) if(q->==queue_size-1) q->=0; else q->++; q->[q- >]=en_; else printf("\nqueue Full"); Circular o Dequeue int deq(arr_queue *q) int de_=null; if(!isempty(q)) de_=q->[q->]; if(q->==q->) q->=queue_size; q->=queue_size; else if(q->==queue_size-1) q->=0; else q->++; else printf("\nempty Queue"); return(de_); Circular o Count int count_queue(arr_queue *q) if(isempty(q)) return(0); else if(q->>=q->) return(q->-q->+1); else return((queue_size-q->)+(q->+1)); 19 20

21 o Use Singly Linked List o Declare Header & Linked List count next next null 22 o Declaration typedef struct queue_dat int ; queue_dat *next; queue_node; typedef struct int count;

6 21 o Use Singly Linked List o Declare Header & Linked List count next next null 22 o Declaration typedef struct queue_dat int ; queue_dat *next; queue_node; typedef struct int count; queue_node *; queue_node *; queue; Linked List header o IsEmpty int IsEmpty(queue *q) return(q->==null); o Create void create_queue(queue **n) *n=new queue; (*n)->=null; (*n)->=null; (*n)->count=0; 23 24

7 25 o Enqueue void enq(int en_,queue **n) queue_node *new_node; new_node = new queue_node; new_node->=en_; new_node->next=null; if(isempty(*n)) (*n)->=new_node; else (*n)->->next=new_node; (*n)- >=new_node; (*n)->count++; o Dequeue void deq(int *de_,queue **n) queue_node *q; q=(*n)->; *de_=q->; (*n)->=q->next; 26 if((*n)->==null) (*n)->=null; (*n)->count--; delete q; else *de_=null; o Front void (int *_,queue **n) o Rear void (int *_,queue **n) 27 *_=(*n)->->; else *_=NULL; 28 *_=(*n)->->; else *_=NULL;

8 o Count int count_queue(queue **n) return((*n)->count); o Clear void clear_queue(queue **n) int dummy; while(!isempty(*n)) deq(&dummy,n); o Destroy void destroy_queue(queue **n) clear_queue(n); delete n; Circular o Use Circular Linked List o Header has pointer que point to count que = que->next next next null 31 32

9 Circular o Declaration typedef struct cqueue_dat int ; cqueue_dat *next; cqueue_node; typedef struct int count; cqueue_node *que; cqueue; Linked List header o IsEmpty Circular int IsEmpty(cqueue *q) return(q->que==null); Circular o Create void create_cqueue(cqueue **n) *n=new queue; (*n)->que=null; (*n)->count=0; Circular o Enqueue void enq(int en_,cqueue **n) cqueue_node *new_node; new_node = new cqueue_node; new_node->=en_; if(isempty(*n)) new_node->next = new_node; else new_node->next = (*n)->que->next; (*n)->que->next = new_node; (*n)->que=new_node; (*n)->count++; 35 36

10 37 Circular o Dequeue void deq(int *de_,queue **n) queue_node *q; q=(*n)->que->next; *de_=q->; (*n)->que->next=q->next; if((*n)->que==(*n)->que->next) (*n)->que=null; (*n)->count--; delete q; else *de_=null; 38 Circular o Front void (int *_,cqueue **n) *_=(*n)->que->next->; else *_=NULL; Circular o Rear void (int *_,queue **n) *_=(*n)->que->; else *_=NULL; Circular o Count o Destroy o Clear เข ยนเหม อน Singly 39 40

Ashish Gupta, Data JUET, Guna

Ashish Gupta, Data JUET, Guna Introduction In general, Queue is line of person waiting for their turn at some service counter like ticket window at cinema hall, at bus stand or at railway station etc. The person who come first, he/she